KUALA LUMPUR: The ‘final nail in your coffin’ may one day be your own thumbnail.

An anxiety-riddled young woman in Gold Coast, Australia was alarmed when her right thumbnail broke off completely in 2014 after being compulsively bitten and chewed on for four years.

Courtney Whithorn, 20, became even more distressed when the exposed skin gradually turned completely black – but instead of seeking medical treatment, she hid the problem from her family, friends and schoolmates.

“My hand was just constantly in a fist because I didn’t want anyone to see it,” she told The Sun.

After four years of concealing her blackened thumb from the world, Whithorn decided to address the issue – but purely for cosmetic reasons. In July this year, she consulted a plastic surgeon about having her discoloured digit restored to its original hue.

But the doctor suspected something amiss, and urged Whithorn to undergo a biopsy in Sydney.

The test result stunned not just Whithorn, but her doctors. She was diagnosed with a rare form of cancer known as acral lentiginous subungual melanoma – which her medical specialists tentatively linked to the trauma her thumb suffered from years of nail-biting.

Since her gutting diagnosis two months ago, Whithorn has endured three painful surgeries to remove her nail bed and malignant skin cells. But the melanoma had started to travel, and that left doctors with just one final option – amputation.

Whithorn said she was stoic over the diagnosis.

“This time, I was much more prepared. (So) I wasn’t scared going for the amputation surgery – just nervous,” she told The Sun.

And so, last week, Whithorn’s thumb was amputated above the knuckle.

Though she is recovering well in hospital, the loss of her thumb is a heavy blow to the university psychology student. Not only was she forced to defer her studies at Griffiths University, Whithorn is now unable to engage in her great passion – writing.

“I love to write. I journal a lot. The thought of not being able to write is definitely a big change for me,” she said.

Whithorn is currently awaiting the results of her amputation, and if she’s given the all-clear, she will be monitored for the next five years through regular scans and blood tests to make sure that she’s cancer-free.

And though she’s lost a thumb, she’s gained a helping hand in coping with her ordeal – in the form of her high school sweetheart, Tyson Donnelly, 20 and her loving parents.